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Related papers: Outers for noncommutative H^p revisited

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We extend some classical constructions in commutative algebra to the setting of modules over orders in (non-commutative) semisimple algebras. Our theory incorporates, inter alia, `reduced' versions of the notions of higher Fitting…

Number Theory · Mathematics 2025-09-16 David Burns , Takamichi Sano

Let $A$ be an expansive dilation on $\mathbb{R}^n$, and $p(\cdot):\mathbb{R}^n\rightarrow(0,\,\infty)$ be a variable exponent function satisfying the globally log-H\"{o}lder continuous condition. Let $H^{p(\cdot)}_A({\mathbb {R}}^n)$ be the…

Classical Analysis and ODEs · Mathematics 2020-11-20 Wenhua Wang , Xiong Liu , Aiting Wang , Baode Li

We present two classes of examples of Hopf algebroids associated with noncommutative principal bundles. The first comes from deforming the principal bundle while leaving unchanged the structure Hopf algebra. The second is related to…

Quantum Algebra · Mathematics 2022-01-06 Xiao Han , Giovanni Landi , Yang Liu

Let $G$ be a free product and $\mathrm{Out}(G)$ the outer automorphism group of $G$. In this article using the theory of laminations we give a criterion for a subgroup $H$ of $\mathrm{Out}(G)$ to contain a nonabelian free subgroup. We also…

Group Theory · Mathematics 2023-09-12 Ioannis Papavasileiou , Dionysios Syrigos

A version of Auslander theorem is proven for the following classes of noncommutative algebras: (a) noetherian PI local (or connected graded) algebras of finite injective dimension, (b) universal enveloping algebras of finite dimensional Lie…

Rings and Algebras · Mathematics 2017-10-18 Y. -H. Bao , J. -W. He , J. J. Zhang

We generalize to the setting of Arveson's maximal subdiagonal subalgebras of finite von Neumann algebras, the Szeg\"o $L^p$-distance estimate, and classical theorems of F. and M. Riesz, Gleason and Whitney, and Kolmogorov. In so doing, we…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Louis E. Labuschagne

In this paper we initiate the study of composition operators on the noncommutative Hardy space $H^2_{\bf ball}$. Several classical results about composition operators (boundedness, norm estimates, spectral properties, compactness,…

Functional Analysis · Mathematics 2011-11-15 Gelu Popescu

Theory of matrix factorizations is useful to study hypersurfaces in commutative algebra. To study noncommutative hypersurfaces, which are important objects of study in noncommutative algebraic geometry, we introduce a notion of…

Rings and Algebras · Mathematics 2021-08-05 Izuru Mori , Kenta Ueyama

We show that the exterior algebra of a vector space $V$ of dimension greater than one admits a one-parameter family of braided Hopf algebra structures, arising from its identification with a Nichols algebra. We explicitly compute the…

Quantum Algebra · Mathematics 2025-12-01 Rinat Kashaev , Vladimir Mangazeev

Let p=tp(a/A) be a stationary type in an arbitrary finite rank stable theory, and P an A-invariant family of partial types. The following property is introduced and characterised: whenever c is definable over (A,a) and a is not algebraic…

Logic · Mathematics 2013-12-19 Rahim Moosa , Anand Pillay

We show that for any subgroup $H$ of Out($F_N$), either $H$ contains an atoroidal element or a finite index subgroup $H'$ of $H$ fixes a nontrivial conjugacy class in $F_N$. This result is an analog of Ivanov's subgroup theorem for mapping…

Group Theory · Mathematics 2024-06-14 Matt Clay , Caglar Uyanik

Let G be a finite abelian group with |G|>1. Let a_1,...,a_k be k distinct elements of G and let b_1,...,b_k be (not necessarily distinct) elements of G, where k is a positive integer smaller than the least prime divisor of |G|. We show that…

Group Theory · Mathematics 2011-04-14 Tao Feng , Zhi-Wei Sun , Qing Xiang

We characterize removable sets for H\"older continuous solutions to degenerate parabolic equations of $p$-growth. A sufficient and necessary condition for a set to be removable is given in terms of an intrinsic parabolic Hausdorff measure,…

Analysis of PDEs · Mathematics 2025-12-18 Michał Borowski , Theo Elenius , Leah Schätzler , David Stolnicki

Let $M$ be a free module of rank $m$ over a commutative unital ring $R$ and let $N$ be its free submodule. We consider the problem when a given element of the exterior product $\Lambda^pM$ is divisible, in a sense, over elements of the…

Commutative Algebra · Mathematics 2022-04-04 Bronisław Jakubczyk

Suppose $G$ is a simple algebraic group defined over an algebraically closed field of good characteristic $p$. In 2018 Korhonen showed that if $H$ is a connected reductive subgroup of $G$ which contains a distinguished unipotent element $u$…

Group Theory · Mathematics 2024-10-22 Michael Bate , Sören Böhm , Benjamin Martin , Gerhard Roehrle

A $Z_3$-graded Hopf algebra structure of exterior algebra with two generators is introduced. Two covariant differential calculus on the $Z_3$-graded exterior algebra are presented. Using the generators and their partial derivatives a…

Quantum Algebra · Mathematics 2016-06-28 Salih Celik , Sultan A. Celik

We classify pointed $p^3$-dimensional Hopf algebras $H$ over any algebraically closed field $k$ of prime characteristic $p>0$. In particular, we focus on the cases when the group $G(H)$ of group-like elements is of order $p$ or $p^2$, that…

Rings and Algebras · Mathematics 2016-09-14 Van C. Nguyen , Xingting Wang

In this version small mistakes are corrected and the exposition is changed as suggested by the referee (to appear in Canadian Journal of Mathematics). The first main result of the paper is a criterion for a partially commutative group $\GG$…

Group Theory · Mathematics 2008-07-28 Montserrat Casals-Ruiz , Ilya V. Kazachkov

We introduce a variable exponent version of the Hardy space of analytic functions on the unit disk, we show some properties of the space, and give an example of a variable exponent $p(\cdot)$ that satisfies the $\log$-H\"older condition…

Complex Variables · Mathematics 2018-11-01 Gerardo A. Chacón , Gerardo R. Chacón

Let $\mathcal{H}$ be a complex Hilbert space, $\mathcal{B(H)}$ be the algebra of all bounded linear operators on $\mathcal{H}$ and $\mathcal{A} \subseteq \mathcal{B(H)}$ be a von Neumann algebra without central summands of type $I_1$. For…

Operator Algebras · Mathematics 2018-05-08 Wenhui Lin